


Cuffed

by incaseyoufic



Category: Ao no Exorcist | Blue Exorcist
Genre: M/M, Okumuracest, Tail Play, Twincest
Language: English
Status: Completed
Published: 2014-08-18
Updated: 2014-08-18
Packaged: 2018-02-13 17:50:43
Rating: Explicit
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 8,196
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/2159655
Author URL: https://archiveofourown.org/users/incaseyoufic/pseuds/incaseyoufic
Summary: <blockquote class="userstuff">
              <p>Yukio employs an unconventional method to strictly supervise his older brother's negligent behaviour. Hint: it involves hand cuffs, tail play, and all the things that naturally follow.</p>
            </blockquote>





	Cuffed

**Author's Note:**

> This story happens before the ending of the anime, so Yukio's demonic inheritance has not manifested yet.

Yukio Okumura was beyond pissed. His supposedly elder brother, Rin, was making a complete ass out of himself, and by proxy Yukio and the entire world of exorcists, and most of all the Vatican.

After the whole incident of Rin going berserk in his fight against Amaimon (seriously, Yukio reflected, this "happy" little Satanic family was ridiculous) and consequently showing his demonic powers in front of his classmates, the Vatican had ruled that if Rin Okumura could not control his behaviour, they would execute him. Rin was to therefore commit himself fully to his studies as an exorcist, earning the next rank, hopefully one day becoming a Knight, and eventually ridding the world of his oh-so-demonic Father.

Yukio grit his teeth and resisted the urge to let out a bark of laughter. Right, as if Rin could or would ever behave himself enough to keep such a low and academic profile. The Vatican had never before encountered such a wild card. Rin had already been walking on thin ice prior to the meeting with Arthur Auguste Angel, and now that ice was cracking. And of course, being the idiot's brother and a far more qualified exorcist, it was Yukio's esteemed job to keep an eye on his other half.

The younger Okumura brother felt his eye twitch and sighed, rubbing his temple, wishing that cram school would end faster. He was attempting to teach the class a lesson on some of the more advanced healing pharmaceuticals and their application in combat. The entire class was in rapt attention (as usual Shiemi even more so), except for of course, Rin. Yukio didn't need x-ray vision to know his older sibling was reading manga beneath his table. And, if the barely perceptible flush to Rin's cheeks was any indication, the series was most likely erotic. For some reason this annoyed Yukio even further.

"Rin!" he shouted, banging a hand on the table.

Said boy gave a satisfying jump, tail shooting upright, eyes opening wide at the sudden calling of his name.

"Wh-wha? Yes?!"

Twitch, twitch went Yukio's eye. "Would you care to repeat to me what I just said? Or would you like to share what you have beneath your desk?"

The rest of the class collectively rolled their eyes. Izumo glared openly at Rin, knowing that the rest of their session would most likely disappear in what was now almost a daily lecture to Satan's offspring.

"Erm, I, uh…" Rin stuttered, red-faced. He sighed and his tail drooped sadly; he knew it was a lost cause. But really, who could blame him – his manga had really been heating up. Then Yukio had had to go and kill the mood! Still, he was supposed to be trying to be a good student, if only to keep the Vatican off his back. He sighed again and bowed his head, averting his eyes from the angry turquoise ones staring him down. "Sorry, prof. I'll put it away."

"No, I don't believe you will. Bring it to me, now."

Rin blushed and glared at his brother. Damn, not another volume confiscated! Rin had never been able to find Yukio's secret stash of manga, but damnit, when he did…

Silently, Rin rose from his desk and carried the small paperback to the front desk, trying to shield the cover from the rest of his classmates' curious glances.

Yukio rose an eyebrow at the cover, not at all expecting to see two male characters on the front. He had assumed… but then, Rin was hardly ever exactly normal. Also, he really did not care what porn his older brother read.

And since this was the fourth time in the week Yukio had had to confiscate Rin's questionable reading material during class, and that it was a Friday with no upcoming known missions, Yukio decided that the weekend was the perfect time to teach Rin a real lesson it what it meant to piss off his younger brother.

"See me after class," Yukio muttered fiercely to Rin.

Rin tried not to appear too nervous as he nodded and sat back down. Somehow he knew whatever it was Yukio wanted to speak to him about would not be good.

Finally, the class ended. Yukio had managed to salvage the remaining time, ending the lesson feeling pretty pleased with himself and what his classmates had retained about healing methods (in his opinion the most important battle strategy).

"We're going to our dorm," Yukio said shortly, beckoning Rin to follow.

"You'd better give me back all that manga you've stolen," Rin bit out, pouting as he followed his brother. "It was expensive…" he muttered.

"Money you could have spent on equipment for exorcisms," Yukio sighed. Rin said nothing. "Rin, we've had this discussion countless times. Obviously you're deaf to my advice about your life, so you clearly need more effective, practical teachings."

Despite himself, Rin began to feel curious as to where Yukio was going with this. Truthfully, Rin was taking all of Yukio's advice about the Vatican to heart, but… well, he had just wanted to work in a shop or something after Junior High. His old man had never mentioned anything about going to more school when he'd given him Mephisto's number. He really hated school, and school hated him. It was not a good relationship.

The twins made it back to the dorm.

"So, what's this practical lesson then, oh wise one?"

Yukio glared at Rin, trying to maintain the seriousness at hand. "You'll see soon enough."

Yukio went to his closet, rummaged for a second, then pulled out –

Rin snorted. "Kinky, Yukio. What are those for? I mean it's not like you're the police or anything."

In his brother's hand were a shiny new pair of handcuffs. Of course he'd never had to use handcuffs to apprehend perpetrators; he just shot them down, plain and simple. Yukio steadfastly ignored the "kinky" comment, refusing to think about the image of the manga cover burned into his eyes.

"As it is now Friday, and there are no upcoming missions that we know about, you, my dear brother, shall be handcuffed with me for the next 24 hours."

"Yukio, you – you can't be serious!"

"If," Yukio continued in a stern, loud voice, ignoring his brother, "you continue to misbehave, I will extend the sentence by another 10 hours. This will continue until you've learned that misconduct on your part could literally kill you."

Rin fumed at Yukio, arms held tightly against his sides, angry that his brother was right.

Yukio's eyes softened a bit. "Rin, please, I'm doing this for your own good. The Vatican has you on an extremely tight leash. If you continue to disregard your studies-"

"Hey! I am not disregarding them! I did my homework last night and everything!"

"Reading yaoi does NOT count as homework!"

A furious blush stole Rin's cheeks and he spluttered. "I – what? I wasn't – I wasn't reading yaoi! It's – just the cover is-" His tail twitched madly behind him, something Yukio had recently learnt meant its owner was lying.

"I don't care what your manga tastes are!" Yukio interrupted loudly, surprised that he actually didn't care – actually, he secretly quite liked that his brother was so open-minded. The boy was clearly bisexual, if his manga interests could be taken to heart. "I just care that you make the next ranking! And at this rate, you will not, and the Vatican will shorten the leash even more, until it no longer can be. You understand?"

"Keh, whatever," Rin bit out, turning away from Yukio, arms still crossed over his chest, still blushing madly. Goddamnit, why did I have to bring my ONE freakin yaoi novel to class? Ergh…

Rin heard a metallic clinking noise and suddenly Yukio was on him, taking his arms and slapping one cuff to his left wrist, the other cuff to his own right wrist.

"There, that means you can write with your right hand now."

Rin glared at the offending ring of metal around his wrist. "What about you? You're also right handed."

Yukio shrugged. "I'm ambidextrous."

Rin rolled his eyes and sighed. "Why am I not surprised. I bet all genius-prodigies can do everything with both hands."

And so the 24 hours cuffed to his brother had begun. Yukio distantly wondered who had the worse deal; after a split second he definitely knew that he himself at the worse deal. Rin would no doubt benefit from their situation. Surely.

Rin sighed again. He was restless, both legs bouncing up and down, tail twitching madly.

"So what now? It's a Friday night, can't we-"

And Rin should have expected this answer from the very beginning of his foolishly naïve question.

"Homework."

Rin slumped forward and groaned. "Goddamnit you're a sadist."

"Oh stop being so melodramatic."

They had barely gotten through the first assignment and Rin's tail had whacked Yukio in the face three times. Distantly, Yukio could admit that at a softer impact velocity the soft black fur might feel nice, but at the moment it was fully irritating, and even more distracting.

"Rin!"

"What!? I'm doing it right, you JUST said so!"

Yukio pinched the bridge of his nose. "NO, it's you're goddamn tail! Can't you control it?"

WHACK!

This time Yukio's poor innocent glasses were the victim. Twin sets of eyes followed their sad trajectory to the floor, where they thankfully remained in-tact.

A loud bark of laughter escaped Rin before he could help himself.

"S-sorry! I can't control it! It does whatever the hell it wants, really." Rin said, wiping tears of mirth from his eyes.

Yukio narrowed his eyes at his brother. "Oh I doubt that. It's definitely tied to your subconscious."

The corners of Rin's mouth twitched upwards, eyes light with mischief. "Now why would I want to repeatedly whack you in the face when you're being so nice and helpful?"

"Whatever. Just continue. You were on question fifteen."

They reached question twenty before Yukio snapped.

Quick as lightning his hand darted out and caught the infuriating black tail, grasping tightly in the middle.

"GAH!" Rin winced and jumped about half a foot out of his seat, almost uprooting the desk. "Y-Yukio, let go, damnit!" He almost shuddered at how damned good it felt to have a warm hand grasping his tail. When Amaimon, the bastard, had grabbed it in the middle of their battle, it had been unforgivingly tight, almost like a vice. Agonizing pain had ripped through his core, the tail the source. But this time, Yukio had not meant to cause pain, instead his only goal to stop the tail from moving so much. A demon's tail was his weakest point, and now Rin could definitely see why. The appendage was extremely sensitive; he could almost feel the very fingerprints of Yukio's digits. Rin squirmed in his seat, suddenly feeling very hot. No, no no nonononono this is NOT happening!

"Will you quit trying to whack me in the face then?"

He grasped the tail a bit harder and shook it in Rin's face slightly, trying to emphasize his point. Yukio hadn't seem to notice yet that his older brother was practically writhing in seat from the pleasure Yukio was indirectly causing him.

This time Rin couldn't hold in his shudder of pleasure. He sagged and let his head drop to the desk, mouth slightly open. "Guh…" he moaned. His eyelids fluttered unevenly and he suddenly felt very weak and very warm. He was probably drooling and he didn't even care. If he could just… rub his hand up and down –

At once Yukio let go, dropping the sensitive appendage, leaving a burning sensation behind.

"Ah, um, sorry Rin. I – I didn't know what that would feel like," Yukio stammered out, feeling extremely embarrassed. He tried to avert his eyes from his brother; his head lay on the desk, cheeks flushed, lips parted, eyes heavy and glazed. Don't look at his crotch, do NOT look at his crotch! "Ah, are you um, okay?"

Rin took three deep breaths and sat up, shaking his head vigorously. Embarrassment flooded away the arousal and he couldn't meet his brother's eyes. "Whatever. Back to homework?" Or a cold shower?

And damnit, now Yukio was extremely curious about demon tails and how sensitive they could be. Were they equally sensitive all along, or were there certain points of peak sensitivity? His fingers were almost itching to experiment, mind distant from whatever assignment his brother was attempting to complete. With resolve he shook himself back into reality.

"Right, so, question twenty."

Amazingly, there were no other incidents for the rest of the evening. Rin cooked a delicious meal for them both and then they went to bed.

Well, tried to go to bed. There was now the new obstacle of having about a foot of space between their bodies.

Rin glared at his brother while Yukio stared blankly at the fifteen foot gap between their beds.

"This is entirely your fault, genius."

Yukio scratched his nose and fully admitted to himself that maybe he didn't quite think this far ahead. Well, it was only for 24 hours… he hoped.

"We'll have to take the mattresses off the beds and just put them on the floor," he decided.

Rin sighed loudly and tugged Yukio over to start with his mattress first, trying desperately to murder the spontaneous population of butterflies that were having a party in his stomach. After a touch of incoordination (it was difficult lifting a double mattress when your arm was attached to another person's), they had both mattresses on the floor.

Rin frowned. "What about the crevasse in the middle? I'm totally gonna fall in, and then you'll follow, and it's gonna suck."

Yukio rolled his eyes, but couldn't argue that Rin had a point. Any gap between the two beddings would undoubtedly widen throughout the night and then the two occupants would be sleeping on the floor.

"One mattress then?"

Rin wouldn't be surprised if he started barfing butterflies. Why the fuck was he so nervous to sleep next to his twin brother? They'd done it before! Okay, maybe the last time had been just before their twelfth birthday, but still! It wasn't like it was weird or anything!

Except that now they were handcuffed together and not hours before Rin had almost came in his pants from Yukio just touching his goddamn tail for Satan's sake. Everything was different now, and it most certainly was weird. And neither of them was actively acknowledging what had happened, and if there was a potential for subsequent occurrences. Throughout the rest of their homework session (during which Yukio had actually been very helpful) Rin had kept shooting his brother furtive glances, all of which had been avoided.

And what was worse, Rin found himself craving that intense pleasure again. It was rare that anyone touched him, sensually or not, and he definitely had never touched his own tail, aside from cramming it inside his shirt or pants for classes. It had been… exhilarating down to his very core, and his sixteen-year-old body definitely did not give two shits who had caused the sensation. Despite his best efforts there was still a lingering arousal sitting heavy in his gut.

And if Yukio's theory was correct, and his tail was somehow connected to his subconscious, then Rin was very much screwed. In the realm of sleep and dreaming, the subconscious reigned supreme, and it very much wanted to continue what had been started during the earlier homework session.

The clearing of a throat gained Rin's attention.

"I need to change out of my work clothes," Yukio muttered.

Rin felt himself being yanked over to Yukio's side of the dorm room, to his closet.

"How the hell are you going to get your shirt off with the hand cuffs?"

"Damn," Yukio muttered.

Rin snorted. "Idiot. Just undo them while we change. I swear I'll be a good boy and not run away," he said somewhat mockingly.

Yukio glared at his brother, knowing there was no other way. "It's ridiculous that I even felt it came down to literally chaining you to me to keep you out of trouble."

Yukio ignored his brother's ranting reply to unlock the cuffs. He swiftly changed, grabbed Rin's wrist and slapped the metal ring back on, distantly surprised the other boy hadn't caused more trouble for them both.

"Uh, idiot, I still need to change. I'm not sleeping in my school clothes."

Yukio huffed and undid the cuffs again.

Rin took a stupidly long time to change, perhaps basking in his short-lived freedom. Yukio tried to be annoyed, but his focus was suddenly yanked to the swaying black tail attached to his captive. He felt like a cat, hypnotized by a swinging piece of yarn. He shook his head violently, clearing his head.

He was just tired. Obviously.

Goddamnit Rin.

Changed and ready for bed the twins settled down onto the mattress on the floor, separated by the foot of space allowed by the metal chain.

Rin sighed, a soft smile on his face.

"Remember when we used to do this as kids?"

Eyes closed, Yukio raised his eyebrows. "What, lie together handcuffed?"

Rin blushed despite himself. "No, idiot. Share a bed."

Yukio allowed a soft smile. "Dad would read us a story…"

A soft punch landed on Yukio's arm. "Way to make it sad."

"Sorry…"

"Try to get some sleep."

"What are we gonna do tomorrow?"

Sigh. "I don't know yet."

"It had better be something more exciting than just studying. I'll go bat-shit insane."

"Just be quiet and go to sleep, Rin."

Silence lasted for about three minutes before Rin huffed, shuffling restlessly, frustrated with the lack of movement allowed by the constricting chain.

"Goddamnit…"

"Lie still, already!"

"I like sleeping on my stomach! Come on, you know that!"

Yukio rubbed a hand over his face, beginning to regret the decision to restrict the movement of a restless half-demon.

"Well we're going to have to compromise. I prefer to sleep on my back."

Both twins shuffled and shifted until they met halfway, as comfortable as they could be, both facing each other, Rin slightly on his stomach, almost on top of his brother.

"This is your worst idea ever," Rin muttered into his pillow.

Yukio swallowed his agreement.

"Goodnight, Rin."

"Hmm."

The darkness in Rin's closed eyes was unfortunately the perfect canvas for all the images he had seen throughout the day…. His manga, where two young men had just begun a sexual relationship; Yukio's shocked and slightly red face when he'd realized the effect he'd had on Rin by grasping his tail… Rin's stomach flipped and he bit his lip, breathing deeply as he told his mind and body to shut up because this was definitely not appropriate. His teenaged body might not care who had caused him pleasure, but his mind definitely – probably – did.

Behind him he both heard and felt his tail shifting. He dared not touch it – would it be like masturbating? Oh God, he didn't even want to think. It was all so fucking weird. He tried to will the damned appendage to be still, or else –

"Rin, control that thing or I will," Yukio mumbled sleepily.

Rin's eyes shot open and his heart skipped a beat. Does he even know what he said?

"Yeah yeah, sorry," Rin muttered back.

The tail didn't seem to care about Yukio's opinions. The black tuft of fur ending the tail swept upward to land near the boy's ear.

Yukio sighed in annoyance and on reflex batted away the fur.

Even that small contact was enough to make Rin shudder. He ignored the warmth spreading in his gut. The lingering arousal from the earlier incident was sparked now, stubbornly refusing to dissipate. It was a primal feeling – the tail itself being a purely animal entity reducing the human side of Rin down to a something simpler.

"D-don't," Rin whispered urgently.

"Well then make it still," Yukio mumbled back, woefully ignorant to just how that small innocent touch had affected his brother.

"I can't, you dumbass. I told you, it does what it wants." At least I can keep telling myself that.

The tail swept closer to Yukio as if it was heeding the dark and deep desires of its owner. Yukio blew out a breath onto its tip, trying to send it away without touching it.

The hot air landed on the sensitive hairs and Rin whined. He slapped a hand to his mouth in disbelief of the mortifying sound he had just made.

"Get a hold of yourself," Yukio mumbled, starting to feel uncomfortable.

"Then stop fucking touching my tail! Just – just ignore it! It's really sensitive okay?"

"I know." A pause. "Sorry."

Goddamnit, there was no way Rin was going to be able to fall asleep now. He was too aroused, too freaked out, and too worried about what his infuriating tail would do next.

"But seriously, you need to move it out of my face or I will."

Rin whined again, this time in frustration and grabbed his tail, wedging it in between them.

Right into Yukio's right hand.

Rin choked. He stilled, breaths short, mouth open.

"Rin… what the hell…"

"I didn't mean to, Oh God…"

A low growl mixed in to Rin's voice and he was mortified at how husky he sounded. He was fucking horny now, and there was no going back. He needed to deal with it and it could not be with his brother, but goddamnit they were handcuffed together and –

Rin groaned, the sensations overwhelming him. He squeezed his eyes shut, his whole body tingling as Yukio moved his hand away from the tail, the metal clinking in the tense silence. Without knowing it Rin started rutting against the warm solid body next to his.

On reflex Yukio moved away, only succeeding in pulling Rin to lie on top of him. He gasped when he felt the heat of his brother's erection pressing into his thigh.

"Rin! Get off!"

RIn choked out a breathy laugh. "I can't, you dumbass! And I would LOVE to 'get off' but I really don't think you'd want that, now would you? Just un-cuff me and I can go deal with this on my own!"

Yukio made a strangled sound and threw back the blankets, brain on overdrive. He grabbed the handcuff key from the desk, trying to ignore the hot and bothered body of his brother pressed against him, trying to slow his racing heart. What the fuck is happening right now?!

With trembling hands Yukio uncuffed Rin from him for the third time that evening, watching in disbelief as Rin ran to the bathroom, knowing full well he was going to bring himself to orgasm, all because he had touched his tail a few times. Unbelievable…!

Yukio lay on the bed, wishing the wall of the bathroom was thicker, trying to ignore the heated moans and gasps permeating through to his ears. Another short minute and Rin gave a choked, gasping moan, then there was silence. Yukio swallowed, his throat suddenly dry. It had only taken his brother a minute to reach orgasm… that means he had been dangerously aroused when they had been lying together.

\--

Rin couldn't take it anymore. He bolted to the dorm bathroom, slamming the door shut behind him. His heart leapt in his throat – he was about to masturbate because his twin brother had unknowingly aroused him to the breaking point. His erection throbbed in his sweatpants, aching to be touched. He moaned as he hastily shoved his pants down, not caring if his brother heard. His fault anyways.

With his right hand he gripped his throbbing erection. Not enough. He groaned in frustration, frenzied with need. The damned tail flitted in front of his gaze and he grabbed at it with his left hand, rubbing up and down the long furred shaft as he pumped his cock. He shuddered and moaned, gasping as he neared completion. A dangerous pleasure coiled in his gut and in what seemed like no time at all he was coming, spurting into his hand. He slumped back against the toilet bowl, panting; it had been without a doubt the most intense orgasm he'd ever had. He groaned again, mortified at how this whole situation had started. He was almost too embarrassed to return back to the bed. He wondered if his brother would even reinstate the whole handcuffing deal. Rin wasn't sure how he felt about that; was he disappointed, or…

\--

Silently Rin made his way back to the bed. Yukio said nothing, but was evidently awake if the blush staining his cheeks was any indication.

"No handcuffs. The door will just remain locked," the younger twin muttered, eyes still closed. "In case you have to… use the bathroom again."

It took a stupidly long amount of time for Rin to fall asleep, in most part because of Yukio's last comment. This time the bothered half-demon lay directly on his infernal tail to keep it in its place.

The next morning was decidedly awkward. Rin was attempting to pretend nothing had happened - that he had not brought himself to an intense orgasm because his brother had played with his tail – and Yukio was trying, and failing, to avoid looking at his brother at all.

But Yukio wasn't giving up on disciplining Rin, so the handcuffs returned for a second trial. When he'd thought of using handcuffs to keep an eye on his brother, Yukio never would have imagined what would happen… certainly not what had happened. A part of him – and he was ashamed to admit this – was excited to think about the possibilities of their changing relationship. Ugh, he wanted to slap himself.

"So what are we gonna do today?" Rin asked, trying not to get his hopes up. His brother had no doubt planned something extremely boring. He very much hoped that they would not be cooped up in the dorms all day working on assignments; they would probably either kill each other, or do… other things. He ignored how his tail twitched at that thought.

"I need to visit Shiemi's Mother's shop to pick up a bulk order of exorcism supplies. We'll see after that," Yukio responded dully.

"What?! No! I don't want Shiemi to see us like this!" Rin spluttered, red-faced, shaking the metal chain, aggravating Yukio's wrist in the process. "That'll be way too embarrassing!"

Yukio rolled his eyes and shrugged. "Yes well, this is the price you pay for always getting into trouble."

Rin wore a scowl the entire walk to the exorcist supplies shop, mortified when anyone even so much as glanced at the twins. They walked closely together, mostly hiding the chain and cuffs from plain sight, but it was still embarrassing.

The usual smoky darkness of the supply shop welcomed the two brothers in from the outdoor sunny heat. The bell chimed, signalling the customers' arrival.

The small blonde girl at the back of the shop jumped a bit and looked up. She greeted them with a bright smile and a small wave, beckoning them to her.

"Hello Yukio! Hello Rin," she grinned.

"Good morning, Shiemi," Yuko said. "Your mother is not in today?"

Shiemi shook her head. "She's out at the local gardening show. I hope she gets some neat new plants!"

"Ah. Well, I've come to retrieve my latest order, if it's not too much trouble for you."

"Oh, not at all! I'll just go get it," Shiemi said enthusiastically, getting up from her stool. Her eyes darted towards the two brothers, noting how closely they were standing, and how uncomfortable Rin seemed. A closer look let her notice the glint of metal in between their hands and her eyes widened, a blush ghosting her eyes. Okumura twins… hand-cuffed together?!

Yukio cleared his throat. "The order, Shiemi?"

"O-oh! Right, sorry! One moment please!"

The two boys waited in tense awkwardness in the dark, musty shop, looking at anything but each other. Rin fidgeted, making the hand cuffs jingle. His friend had definitely noticed his current predicament, increasing his own embarrassment. At least his tail was relatively calm, swaying lightly behind him.

The blushing Shiemi returned with various small packages and vials, placing them on the counter to await Yukio's inspection. After a moment the younger twin seemed satisfied and paid for the items, smiling his thanks at the girl.

"Always a pleasure doing business with you, Shiemi," Yukio said, collecting his order in his hands and passing some to Rin's free hand. The hand cuffs jingled loudly, puncturing the otherwise silence of the dim shop. Rin and Shiemi sported identical blushes and Yukio could have laughed if he wasn't so embarrassed himself.

"Er, Yukio, can I ask why you and Rin are chained together?" Shiemi asked, biting her lip.

"This bastard thinks he needs to keep me on a leash or I'll be free to destroy the school. Or something," Rin muttered, glaring daggers at his twin.

Yukio sighed, rolling his eyes. "Don't be so dramatic, brother." He did not elaborate further, however, leaving Rin looking murderous and Shiemi even more curious.

"So then why…" Shiemi's overactive imagination made her give a tiny squeak and her face turned the colour of a tomato. She shook her head violently, dispelling any fantasies of shirtless twins.

"I found Rin's behaviour troublesome. Clearly he requires constant supervision, so hence my unfortunately drastic measures," Yukio explained, raising their conjoined hands, the metal clanging.

"Jerk," Rin grumbled.

Yukio shrugged. "It's only until he learns his lesson."

"Oh, well, okay then. Good luck Rin!" Shiemi gave Rin a bright smile. The half demon pouted and avoided her optimistic gaze.

"We shall be going now," Yukio said, starting to turn away, tugging Rin along with him.

"What? No way! I want to help out in the garden for a bit. Stretch out my legs!" Rin tugged his arm away from his brother, glaring at him.

Shiemi giggled as the two brothers struggled out of the door, one yelling at the other. They were quite a funny pair. She sighed and sat back on her stool, cupping her cheek in one hand. Now that her customers were gone, she was free to allow her mind to wander to less than appropriate places.

\--

A few hours later, after running several more errands, the two Okumura twins found themselves back in their dormitory, doing yet more homework, much to Rin's distaste.

Rin sighed loudly, slumping in his chair. "Man, this exorcist stuff is hard work. I'm definitely better at the fighting and action gig than the reading books gig."

"Yes, well, both are important to realizing your full potential."

"Whatever."

Yukio sighed. "Look, we're actually almost finished this assignment. Then we can-"

Muffled voices crept through the door and a second later there was a sequence of knocks.

"I'll get it!" Forgetting that they were chained together, Rin burst up from his chair, glad for any reason to interrupt this monotonous homework session. Yukio cringed in pain when the hand cuff scraped at his wrist with Rin's violent movement.

"Ouch, you idiot, that hurt!"

"Come on, let's go see who it is!" Rin said happily, ignoring his brother's obvious discomfort.

At the door were Konekomaru, Ryuji and Nemu. The brunette was smirking and twirling a soccer ball in his hands.

"Yo," he said to Rin. "Wanna go play a game?"

"It's really nice out," Konekomaru added.

Rin slumped in defeat, groaning in misery. "Guys, I can't, I'm stuck in here doing homework all day with this guy," he said, tugging Yukio into full view.

"Oh, hello Professor," Konekomaru said, slightly surprised.

"Er, why are you guys…"

"Don't ask," Rin growled out. He turned pleading eyes to his brother, extremely annoyed at the whole situation, wanting, needing to go outside and let off some steam. The last hour of sitting closely to his brother had been torture on his nerves. He'd been unable to keep his mind from recalling the events of the previous night, how he'd gotten off on his brother touching his tail. He needed to get away from the other boy for a bit. "Can I go just for a bit?" He was not whining. Definitely not.

Yukio shook his head. "No, we're almost done." He turned to face his students. "Sorry boys. Go enjoy the nice weather for us both."

"But-"

Yukio sighed. Trying to be inconspicuous, he reached down behind him and grabbed for Rin's tail, squeezing the silky appendage in his hand. Rin immediately stiffened and squeezed his mouth shut, his eyes going wide.

"Er, Rin, you okay, dude?" Ryuji asked, peering at his friend with narrowed eyes.

"Yup," Rin said through gritted teeth. "Bye guys, sorry." He slammed the door shut, promising to apologize to his friends again later. As soon as the door was closed, he rounded on his brother, who sheepishly let go of his tail. "What the HELL, Yukio! You can't just – you – urgh!" He buried his blushing face in his free hand, carding trembling fingers through his hair.

Yukio just stared at his flustered brother, realizing now that hand cuffs and strict supervision were quite unnecessary to keep Rin in check. Clearly, touching the boy's demon appendage was instantly effective at distracting Rin from anything happening around him. On the downside though, the contact left the boy in an awkward state of arousal. Feeling his face heat up, Yukio cleared his throat, eyes darting away from his brother's flushed face.

"Er, do you need to use the bathroom again?" He reached into his pants' pocket to fish the small silver key out to unlock the hand cuffs.

Rin shook himself violently, exhaling hard, forcing himself to calm down. "No. No, I should be okay. Just – just don't do that again, okay? I'm already on edge enough as it is," he said, biting his lip. He hadn't really meant to say that last part out loud. He wiped his hands on his pants in a nervous gesture, then nodded in the direction of the desk. "Let's just finish the damned homework. And then we can, I dunno, play a game or something."

Or something. "Sure," Yukio nodded. Rin was "on edge"? Something in Yukio's gut squirmed, sending a hot rush of mild pleasure to his groin. He groaned internally. Damn, he did not need this – this lust for the boy sitting beside him. It was completely irrational to feel this way. This had been such a stupid mistake – what the hell had he been thinking, chaining Rin to him in such intimate proximity? His original intention to be his brother's supervisor had somewhat backfired. All he had to show for it was an unhealthy curiousity about the tail that was apparently so damned sensitive. He couldn't help it, his brother's reactions were interesting, and made Yukio's teenage body react, even if those reactions were completely inappropriate. And now Yukio couldn't help but focus on his brother's admission of being "on edge", which surely meant the boy was aroused. If Yukio touched his brother's tail one more time, then…

The silky black appendage was hanging heavily from Rin's lower back, the tip of it curled up from the floor. Yukio looked at his brother's face, noting that he actually seemed to be concentrated on the assignment (for once). It was almost too bad, cutting off Rin's determination to do homework, because getting Rin to focus more on academia had been Yukio's original intention after all. But Yukio now found himself too curious to resist. Slowly, heart thrumming in his chest, he reached his free hand out towards the tail. As soon as his fingertips came in contact with the silky black fur, Rin's head fell limply onto the desk with a light thud, his pen rolling out of his hands.

Rin's uneven breaths were short and shallow, falling on his open mouth, making his lips glisten. His head was turned to face Yukio's, who was watching him intently, but Rin's eyes were squeezed shut. A red flush tainted Rin's pale cheeks and he pushed slightly back into Yukio's hand, which was now stroking up and down the base of the tail.

"Aaaah," Rin moaned, his voice breathy. He wanted more – his whole body thrummed with pleasure and he let the barriers fall down. Obviously his brother wouldn't have initiated the contact if he was opposed to it, and Rin no longer gave a fuck, as long as he kept doing that to his tail. "M-more," he panted, grinding his forehead into the desk, clenching his hands into fists.

Yukio swallowed past a dry throat and complied with Rin's plead, gripping the now twitching tail firmly, stroking the fur up and down, dragging fingernails through the silky black fur. He swore under his breath and, with shaking fingers, unlocked the hand cuffs, letting them drop to the floor. With both hands now free, he was able to give Rin's tail the attention it needed. There was no going back now – Yukio had begun something, and he damn well intended to finish it, whatever that entailed. His heart beat fast in his chest and he squirmed in his seat, not used to feeling the growing hardness in his pants, not often allowing himself private pleasure to enjoy with his busy lifestyle. He would allow himself to indulge, maybe just this once, in all the carnal pleasures he had been denying himself.

Rin gasped and moaned, his head shooting up from the table, when he felt fingers thrust shallowly into his ass through his shorts, the other hand on his tail starting to move faster. "Oh God, f-fuck," he panted. Bolts of intense pleasure shot through him whenever his brother's fingers curled into his asshole, pressing through his clothes, which was strange because Rin had never thought about his ass as being such a sensitive zone. A moan came with every exhale as he thrust and back into his brother's hand. He was incredibly, dizzyingly aroused.

"I want you to come, just from me touching your tail," Yukio whispered, surprising himself at the bold statement. He was breathing hard, like he had just run a long distance, and all he was doing was moving both of his hands on his brother, arousing the both of them.

Rin moaned louder than before, his brother's uncharacteristically daring words sending sparks of pleasure through his brain, making his blood run hot, making his groin throb. He thrust his crotch upwards, hitting nothing, desperate for friction, but wanting to please his brother. "U-Use both hands then," he gasped, pleasure stealing his voice.

Eager to see his brother completely unravel, Yukio withdrew the hand at Rin's ass and rubbed both his hands up and down the half demon's tail, twisting and stroking and pinching and rubbing. Rin fell back down against the desk, his mouth falling open, darkened blue eyes half-lidded in pleasure.

"Good?" Yukio panted. He leaned his sweaty forehead on his brother's quivering shoulder, their breaths mingling in the air between their mouths.

"Yeah. A-Almost – oh God, Yukiooo," Rin groaned. He bit his lip hard, a sharp canine drawing blood, as his hips jerked wildly. "I'm – I'm coming, fuck!"

Rin's whole body stiffened and he grunted, his hips bucking into the air. He collapsed when it was over, breathless, dark eyes peering up at his brother.

Surely Yukio had lost his mind, because his brother looked extremely sexy to him right now – post-orgasm, dishevelled, limp – and all Yukio wanted to do was take him ruthlessly. He'd never had much interest in sex before, nor had he ever had the time to spare. But now… and when he'd been practically fingering Rin's asshole through his shorts, there had only been positive reactions.

Yukio shut off his brain. As quickly as he could he could Yukio undid his belt buckle. He watched Rin's throat muscles move as he swallowed, blue eyes watching every move of Yukio's trembling fingers as they pushed the trousers down to his knees, revealing that Yukio was just as aroused as Rin was.

"Get on the bed," Yukio ordered, pointing over to his bed.

Rin almost collapsed on his way over; his legs were like jelly, weak from the intense orgasm he'd just enjoyed. He collapsed onto his stomach, letting his ass stick up a bit in the air, assuming that's what his brother wanted. The appreciative groan from behind Rin confirmed his assumptions and he felt another bolt of pleasure and anticipation rock his senses. This new deviant side to his twin brother was so completely different that the usual aloof, calm and collected persona Rin was used to interacting with.

Wasting no time, Yukio roughly shoved Rin's pants and boxers down to bunch behind his slightly bent knees. Rin's tail twitched and swayed, and Yukio held it down with one hand, making Rin groan. Yukio was too aroused, too desperate for an intense release to echo his brother's, but not too impatient to prepare his brother adequately. He backed away from Rin's exposed ass, frowning, eyes searching their bedroom. He stepped off the bed and went to the nearest bedside table, hoping that – yes, thank God, there was a small bottle of oil. What Rin used it for, Yukio didn't want to know – or maybe he did – regardless, he knew what he was going to use it for.

"I'm going to fuck you," Yukio stated, quite unnecessarily, as he generously coated two fingers of his free hand with oil. "But first…"

Rin gasped as, again, he felt fingers prodding near his ass. This time, there was no cloth barrier; skin on skin. He bit his lip and pressed back into the searching fingers, groaning loudly as he felt one fingertip breach the tight ring of muscle of his rectum. It was strange, that it felt so damned good, and Yukio's fingers were so warm. The pleasurable sensation of Yukio's hand still gripping his now hyper-sensitive tail compensated for the slightly uncomfortable feeling of two fingers scissoring his asshole. He was still feeling extremely relaxed from his recent orgasm, but it didn't help too much.

"Three," Rin heard Yukio mutter. Another finger joined the two in Rin's ass and he choked, edging away from his brother a bit, unable to mask his discomfort.

"Just do it, already!"

Both boys groaned as Yukio slowly, steadily pressed his cock into his brother's stretched hole.

"Fuck," Yukio moaned. He heard his brother gasp at the rare swear word. He gripped the tail in one hand, Rin's hip in the other, trying to keep everything still as he felt his brother adjust to his girth. The incredible hot tightness surrounding his cock was unbearably good and he wanted to thrust into Rin with reckless abandon. But he had to wait, otherwise the pain would be too intense for the other boy. Yukio stroked the silky tail in an effort to distract the half demon from the discomfort.

A shiver passed up Rin's skin, making his hair stand on end. "Yeah, keep doing that. Gimme a sec," he panted. After an agonizing few more seconds, Rin groaned and pushed his hips back into his brother, encouraging him to move. On the third thrust Yukio hit Rin's prostrate, making the half demon cry out in pleasure, reviving his erection instantly.

"Oh God, what – what are you doing?" Rin moaned, writhing beneath his brother, impatient for another thrust, for more of that delicious pleasure to shoot through him.

"Basic anatomy," Yukio grunted. His nails dug harshly into the flushed skin of his brother's hips, stopping their movement, their writhing too much for Yukio to handle. He wanted to last a bit longer. "Called the prostate."

"Ah – well k-keep hitting it, fuck!" It was incredible, how a sensation that had not a moment before been uncomfortable and painful was now the most insanely good thing Rin had ever felt. White sparks danced behind his eyelids as he met his brother thrust for thrust. His brother's cock felt so good inside of him, so sinful, but it was somehow so appropriate, because their whole lives had been defined and ruled by sin. Might as well make it pleasurable.

Rin growled, baring his fangs, faint blue flames licking at his skin as his demonic nature began to surface. "F-faster," he moaned, voice husky.

Yukio's thighs quivered with the effort of it. Flesh slapping on flesh, sweat beading on skin. The silky raven tail wrapped around Yukio's waist, trying to bring them even closer. He gasped as he felt the tufted end of the appendage poke and probe at his own entrance, stilling his thrusting. "R-Rin, what-"

"Don't stop, you bastard," Rin said through clenched teeth. He could feel his tail poking at his brother's entrance, the sensitive end furs creating friction, sending tingles down his spine, creating almost too much stimulation. The appendage was definitely connected to his mental consciousness on some level, Rin realized, because he had not a second before been picturing fucking Yukio. A cry of pleasure slipped from his lips as he felt that hard throbbing cock penetrate him again, resuming the brutal pace of before.

It was ridiculous that Yukio could only now feel embarrassment. He had never imagined that his ass could be such an erogenous zone. He supposed it made sense – if Rin liked it, then Yukio, his twin, should likewise enjoy stimulation there. He shuddered as he felt the strong tail push through the tight ring of his entrance. It was certainly a strange sensation. He wondered if Rin was doing it on purpose, then decided he didn't care as long as the sensation continued.

"Gonna – gonna come," Rin moaned. Beneath him, his right hand pumped at his straining erection, giving him that one final push into orgasm. His whole body tense and clenched, making Yukio cry out, his climax triggered from both ends, his cock being squeezed by that tight heat, his ass being shallowly penetrated by his brother's tail. He saw stars for a second, his entire being overwhelmed by the shockingly intense pleasure.

Yukio collapsed on his brother, groaning and trying to regain his breath. They both winced as Yukio pulled out of Rin, a furious blush painting Yukio's face at the trickle of ejaculate running down the demon's thigh.

"Uuuggggh," Rin moaned. "Everything hurts." His tail, for once, lay limply on the bed, not even twitching. He rose up on his elbows, wincing. "Ergh. I need a shower." He felt sticky with sweat and cum, and now that the afterglow of post-coital bliss had disspitated, the pain at his rump was starting to become annoying. "God, sitting in class tomorrow is gonna suck."

Yukio blushed. "Um, yes. It probably will. Sorry."

Rin swung his body around to sit at the edge of the bed. He lightly punched his brother in the shoulder, smirking at him. "I'll forgive ya. But only if you have a shower with me."

Rin laughed as his brother's blush deepened. "Oh you cannot be serious. Embarrassed by a shower after what we just did? Come on." He tugged at his brother's hand, not giving the spluttering dork a chance to reply.

"Rin!" Yuko tugged at his brother's arm, stopping him just as they entered the bathroom. "Wait, I just… um." He bit at his lip, staring wide-eyed into his twin's eyes.

"Seriously, I'm so filthy right now. Shower now."

"Yes, okay. Okay. Just… I want…" Frustrated at this rare lack of coherency, Yukio decided to just stop attempting to communicate his desire to kiss his brother. With one arm he reached out and cupped his brother's cheek, leaning in close. Rin's eyes widened a fraction and, his cheeks dusting pink, met his brother halfway, sealing their lips together.

"Oh…" Rin whispered. He wrapped his arms around Yukio's warm back, leaning in to the kiss, deepening it. After a moment they parted, both red in the face at the unexpectedly tender intimacy. Rin appeared bashful, eyes focusing on his bare feet on the tiled floor. Yukio chuckled and flicked his brother in the forehead, happiness and a strange sense of relief making him feel light.

"So, no more handcuffs?" Rin asked hopefully, meeting his brother's fond gaze.

Yukio sighed, smiling. "No." He smirked. "Now I have much better means to manage your behaviour. Although, using handcuffs now might be more… interesting."

The half demon's brow raised in amused surprise. "Geez bro, I didn't know you were this kinky!"

Yukio laughed, looking a bit embarrassed. "I didn't really know either, to be honest. I blame it on you."

Rin winked at him, smirking. "Shower?"

"Fine, yes. Er, together?"

Rin rolled his eyes and lightly pushed his brother into the shower. "Geez. You're an adorably kinky dumbass."

"That's… a weird descriptive."

"Well congratulations, you're a weird guy."

"I would say we're both equally weird."

"Damn straight. Pass me the soap."

\--

Get it, damn straight? Because they're both damned. And not straight. Hah. Haaaaah. _

"Okumuracest is wrong! 'Tis the work of Satan! They can't – oh wait. Nevermind." – Tumblr.


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